A man gathers freshly-harvested olives under olive trees near the village of Castagniers, north of Nice, France on Dec. 5 last year.一民男子去年十二月五日在法國尼斯北部卡斯塔尼爾村附近橄欖樹下，摘採新鮮橄欖。

Photo: Reuters照片：路透

A plant germ found in Europe for the first time is killing off centuries-old olive trees in southern Italy’s Apulia region, and researchers have not yet figured out how far the pathogen has spread.

Scientists found Xylella fastidiosa, a bacterium native to the Americas, in plants across Lecce province in Apulia’s south, said Anna Maria D’Onghia, head of integrated pest management at the Mediterranean Agronomic Institute of Bari.

The institute is testing plants without signs of infection to determine a protective buffer zone. The germ may have been introduced via the import of ornamental plants, according to D’Onghia.

“We are researching how far the pathogen has moved from this area. Usually when you see the diseased trees it’s too late,” D’Onghia said.

Italy’s agriculture ministry said it was setting up a task force to determine the boundaries of the infected areas and develop a plan to prevent further spread.